A week after sitting out their scrappy 21-21 draw with the Sharks, the fleet-footed pivot scored two tries in the opening 22 minutes and put on a play-making clinic to fuel the red and blacks' bonus point win at Loftus Versfeld.
Romping past the second-placed Bulls propelled the Crusaders seven points clear of the Hurricanes in the New Zealand conference and, with just four regular season matches remaining on their schedule, it was another big stride towards sealing the top seed.
Mo'unga bagged half of the Crusaders' four first half tries as they eased out to a 26-6 lead on the back of a gameplan which demanded they played the game at speed.
Form wing Sevu Reece snared a hat-trick to boost his try-scoring tally to nine in seven games, one off the competition lead, and it was his third which was the pick of the Crusaders' seven tries.
Having set the Crusaders up inside the Bulls' 22 courtesy of a pinpoint cross-field kick to George Bridge some 50 metres back, Mo'unga followed it up with another to Reece, who plucked the ball out of the thin air and touched down.
Clearly, playing on the Highveld does not faze them and it was the Bulls who were forced to suck in the big ones as the Crusaders showed their will to keep ball in hand and run it at every opportunity.
It was not surprising, then, that the Crusaders rattled off 670 metres with ball in hand, more than double the Bulls' 317, the majority of which they conjured late in the fixture.
Mo'unga was the benefactor of a fortuitous bounce from a Bridge grubber kick, which cruelly evaded Bulls first-five Handre Pollard, for his first five-pointer, but there was no fortune in his second.
The 24-year-old used a show-and-go to knife through the Bulls' defensive line, before stepping Pollard to finish off the sparkling 40m run and put the Crusaders 14-0 up after 22 minutes.
The Bulls had their chances. No bigger than the one created when midfielder Burger Odendaal busted through Matt Todd and Ryan Crotty to setup an attacking raid deep inside the Crusaders' 22, only for a halfback Andre Warner to spill the ball at the ruck